<template>
 <div id="home">
   <nav-bar class="home-nav"><div slot="center">购物街</div></nav-bar>
   <tab-control class="tab-control" 
                :titles="['流行','新款','精选'] " 
                @tabClick="tabClick"
                ref="tabControl1" v-show="isTabFixed"></tab-control>
   <scroll class="content"
           ref="scroll" 
           :probe-type="3" 
           @scroll="contentScroll"
           :pull-up-load="true"
           @pullingUp="loadMore">
    <home-swiper :banners="banners" @swiperImageLoad="swiperImageLoad"></home-swiper>
    <recommend-view :recommends="recommends"></recommend-view>
    <feature-view></feature-view>
    <tab-control :titles="['流行','新款','精选']" 
                @tabClick="tabClick"
                ref="tabControl2"></tab-control>
    <goods-list :goods="showGoods"></goods-list>
   </scroll>
   <back-top @click.native="backtop" v-show="isShowBackTop"></back-top>
 </div>
</template>

<script>

import HomeSwiper from './childComps/HomeSwiper'
import RecommendView from './childComps/RecommendView'
import FeatureView from './childComps/FeatureView'


import NavBar from 'components/common/navbar/NavBar'
import TabControl from 'components/content/tabControl/TabControl'
import GoodsList from 'components/content/goods/GoodsList'
import Scroll from 'components/common/scroll/Scroll'



import {getHomeMultidata, getHomeGoods} from "network/home"
import {debounce} from 'common/utils'
import {itemListenerMixin,backTopMixin} from 'common/mixin'



export default {
  name:'Home',
  components:{
    HomeSwiper,
    RecommendView,
    FeatureView,
    NavBar,
    TabControl,
    GoodsList,
    Scroll,
   
  },
  mixins:[itemListenerMixin,backTopMixin],
  data(){
    return{
      banners:[],
      recommends:[],
      goods:{
        'pop':{page:0, list:[]},
        'new':{page:0, list:[]},
        'sell':{page:0, list:[]},
      },
      currentType:'pop',
      tabOffsetTop:0,
      isTabFixed:false,
      saveY:0,
    }
  },
  computed:{
    showGoods(){
      return this.goods[this.currentType].list
    }
  },
  destoryed(){

  },
  activated(){
    this.$refs.scroll.scrollTo(0, this.saveY, 0)
    this.$refs.scroll.refresh()
  },
  deactivated(){
    this.saveY = this.$refs.scroll.getScrollY()
    this.$bus.$off('itemImgLoad',this.itemImgListener)
  },
  created(){
    this.getHomeMultidata()

    this.getHomeGoods('pop')
    this.getHomeGoods('new')
    this.getHomeGoods('sell')
    // 监听item中图片加载完成

  },
  mounted(){
    // 1、图片加载事件监听
    // this.tabOffsetTop = this.$refs.tabControl.offsetTop;
    
  },
  methods:{
    
    // 事件监听相关方法
    tabClick(index){
      switch(index){
        case 0:
          this.currentType = 'pop'
          break
        case 1:
          this.currentType = 'new'
          break
        case 2:
          this.currentType = 'sell'
          break
      }
      this.$refs.tabControl1.currentIndex = index
      this.$refs.tabControl2.currentIndex = index
    },
  
    contentScroll(position){
       
      this.isTabFixed = (-position.y) > this.tabOffsetTop
      this.listenShowBackTop(position)
    },
    loadMore(){
      this.getHomeGoods(this.currentType)
    },
    swiperImageLoad(){
      this.tabOffsetTop = this.$refs.tabControl2.$el.offsetTop
     
    },
    // 网络请求相关方法
    getHomeMultidata() {
      getHomeMultidata().then(res => {
      this.banners = res.data.banner.list
      this.recommends = res.data.recommend.list
    })
    },
    getHomeGoods(type){
      const page = this.goods[type].page +1
      getHomeGoods(type, page).then(res => {
        this.goods[type].list.push(...res.data.list)
        this.goods[type].page += 1
        // 完成了上拉加载更多，bs需要调用finish函数来确定再一次拉到底部
        this.$refs.scroll.finishPullUp()
    })
    }
  }

}
</script>

<style scoped>
#home{
    /* padding-top: 44px; */
     height: 100vh;
     position: relative;
    
}

.home-nav{
  background-color: var(--color-tint);
  color: #fff;

  position: fixed;
  left: 0;
  right: 0;
  top: 0;
  z-index: 9;
}

.tab-control{
 position: relative;
 z-index: 9;
}

.content{
  /* overflow: hidden; */
  position: absolute;
  top: 44px;
  bottom: 49px;
  left: 0;
  right: 0;
}

</style>